1. Field of Invention
The present invention relates to a chip antenna apparatus for receiving global positioning system signals. More particularly, the present invention relates to a chip antenna apparatus with an L-shaped ground area for receiving global positioning system signals.
2. Description of Related Art
The rapid growth in wireless communication, for example, cell phone, computer and Wi-Fi network, makes wireless signal transmission possible. One example of wireless transmission applications is that Global Positioning System (GPS) has been integrated into cell phone to further achieve practical use of cell phones.
The frequency bands for Mobile Communications (GSM) are 900 MHz and 1800 MHz and are different from the GPS frequency band which is 1575 MHz, so different antennas are required for foregoing different functionalities. Further, GPS signal is a circular polarization signal which is different from the linear signal for GSM. Therefore, there is a need for cell phone to have a GPS antenna which is connected to the GPS receiver circuit integrated in the cell phone.
Conventional GPS uses a patch antenna to receive the circular polarization signal. The patch antenna is a directional antenna, capable of receiving the wireless signal. However, if patch antenna is used in order to integrate GPS functionality into cell phone, the patch antenna only receives satellite signal from specific directions. This affects reception of a moving cell phone (without fixed position and direction), so the positioning problem will be caused by interrupted satellite signals.
For the foregoing reasons, there is a need to overcome the weak signal and inaccurate positioning problem when integrating GPS with conventional cell phone which only receives signal from specific directions.